Since even before the U.S. Declaration of Independence in 1776 and the creation of the Continental Army in 1775, a cognitive tension has always existed between civil authority and military planners. This tension creates gaps between the political strategy and military tactics. The clock metaphor will show that three critical components of war affect how the military planner practices operational art. These components-the value of the political object being sought, the duration, and the magnitude of effort-establish casual relationships that shape the conduct of war. To illustrate this relationship, this book will examine one case study: the Vietnam War from 1955 to 1975. The three time periods examined in this case study clearly illustrate the cognitive tension and relationships that the operational artist must acknowledge and account for when employing forces in time, space, and purpose. The clocks add nuance to military planners' understanding of the dynamics of strategy, operational art, and tactics. Examining combat operations during the Vietnam War through a clock metaphor serves to illuminate operational planning tendencies; it becomes apparent that operational planners must consider ways to keep the theater clock synchronized with or ahead of the Washington clock. Planners must understand the implications and constraints of the domestic political atmosphere in order to account for this phenomenon in the planning process. Couching the three components as lessons learned or relearned in the operational environment of today, establishes a framework that is useful for operational planners.